Fourier ptychographic x-ray imaging systems, devices, and methods

Patent metadata

Field	Value
Publication number	US-9892812-B2
Application number	US-201314065305-A
Country	US
Kind code	B2
Filing date	Oct 28, 2013
Priority date	Oct 30, 2012
Publication date	Feb 13, 2018
Grant date	Feb 13, 2018

Abstract

Methods, systems, and devices of Fourier ptychographic X-ray imaging by capturing a plurality of variably-illuminated, low-resolution intensity X-ray images of a specimen and computationally reconstructing a high-resolution X-ray image of the specimen by iteratively updating overlapping regions in Fourier space with the variably-illuminated, low-resolution intensity X-ray images.

First claim

What is claimed is:

1. A Fourier ptychographic X-ray imaging system, comprising:
an X-ray optical element configured to receive radiation issuing from a specimen being imaged during operation;
an X-ray radiation detector configured to receive radiation transmitted by the X-ray optical element and configured to capture a plurality of variably-illuminated, low-resolution intensity X-ray images of the specimen during operation; and
a processor having instructions for reconstructing a high-resolution X-ray image of the specimen by iteratively determining the high resolution X-ray image that is self-consistent with the variably-illuminated, low-resolution intensity X-ray images captured by the X-ray radiation detector, wherein reconstructing the high-resolution X-ray image includes recovering phase image data.

2. The Fourier ptychographic X-ray imaging system of claim 1 ,
wherein the X-ray optical element and the X-ray radiation detector are configured to rigidly move together during operation.

3. The Fourier ptychographic X-ray imaging system of claim 2 , further comprising a mechanism for moving the X-ray optical element, the X-ray radiation detector, and the specimen being imaged together during operation such that X-ray radiation from a stationary X-ray radiation source impinges the specimen from the plurality of incidence angles.

4. The Fourier ptychographic X-ray imaging system of claim 3 ,
further comprising a stage for mounting the X-ray optical element and the X-ray radiation detector,
wherein the mechanism is configured to move the stage to cause the X-ray optical element and the X-ray radiation detector to rotate during operation.

5. The Fourier ptychographic X-ray imaging system of claim 2 , wherein the X-ray optical element is located between the specimen and the X-ray radiation detector.

6. The Fourier ptychographic X-ray imaging system of claim 1 , wherein the X-ray optical element is a zone plate.

7. The Fourier ptychographic X-ray imaging system of claim 1 , wherein the X-ray optical element is a grazing incidence mirror.

8. The Fourier ptychographic X-ray imaging system of claim 1 , wherein the processor also includes instructions for automatically refocusing the high-resolution X-ray image of the specimen.

9. The Fourier ptychographic X-ray imaging system of claim 1 , further comprising a display for displaying the high-resolution X-ray image.

10. The Fourier ptychographic X-ray imaging system of claim 1 , wherein the reconstruction is performed by iteratively updating overlapping regions in Fourier space with the variably-illuminated, low-resolution intensity images.

11. The Fourier ptychographic X-ray imaging system of claim 10 , wherein the overlapping regions overlap by between 40% and 60% in area.

12. The Fourier ptychographic X-ray imaging system of claim 10 , wherein the overlapping regions overlap by 65% to 75% in area.

13. A method of Fourier ptychographic X-ray imaging using a Fourier ptychographic X-ray imaging system having an X-ray radiation detector and an X-ray optical element configured to receive radiation transmitted by the X-ray optical element, the method comprising:
receiving, at an X-ray optical element, radiation issuing from a specimen being imaged during operation;
acquiring, using the X-ray radiation detector, a plurality of variably-illuminated, low-resolution intensity X-ray images of the specimen while the specimen receives X-ray radiation from a plurality of incidence angles; and
reconstructing a high-resolution X-ray image of the specimen by iteratively determining the high resolution X-ray image that is self-consistent with the variably-illuminated, low-resolution intensity X-ray images, wherein reconstructing the high-resolution X-ray image includes recovering phase image data.

14. The method of Fourier ptychographic X-ray imaging of claim 13 , further comprising
moving the X-ray optical element and the X-ray radiation detector such that X-ray radiation impinges the specimen being imaged from a plurality of incidence angles.

15. The method of Fourier ptychographic X-ray imaging of claim 13 , wherein reconstructing the high-resolution X-ray image of the specimen by iteratively determining the high resolution X-ray image that is self-consistent with the variably-illuminated, low-resolution intensity X-ray images comprises:
dividing each variably-illuminated, low-resolution intensity X-ray image into a plurality of tiles to generate a plurality of variably-illuminated, low-resolution intensity tile X-ray images for each tile;
recovering a high-resolution X-ray image for each tile by iteratively determining the high resolution X-ray image for each tile that is self-consistent with the variably-illuminated, low-resolution intensity tile X-ray images for the tile; and
combining the high-resolution X-ray images of two or more of the tiles.

16. The method of Fourier ptychographic X-ray imaging of claim 13 , wherein reconstructing the high-resolution X-ray image of the specimen by iteratively determining the high resolution X-ray image that is self-consistent with the variably-illuminated, low-resolution intensity X-ray images comprises:
(a) initializing a current high-resolution X-ray image in Fourier space;
(b) filtering an overlapping region of the current high-resolution X-ray image in Fourier space to generate a low-resolution X-ray image for an incidence angle of the plurality of incidence angles;
(c) replacing intensity of the low-resolution X-ray image with an intensity measurement; and
(d) updating the overlapping region in Fourier space with the low-resolution X-ray image with measured intensity.

17. The method of Fourier ptychographic X-ray imaging of claim 16 , wherein the steps of (b), (c), and (d) are performed for the plurality of incidence angles.

18. The method of Fourier ptychographic X-ray imaging of claim 16 , wherein the steps of (b), (c), and (d) are iterated until the current high-resolution X-ray image converges.

19. The method of Fourier ptychographic X-ray imaging of claim 13 , wherein reconstructing the high-resolution X-ray image comprises iteratively updating overlapping regions in Fourier space with the variably-illuminated, low-resolution intensity images.

20. A Fourier ptychographic X-ray imaging system, comprising:
a light element configured to pivot, during operation, to provide X-ray radiation to a specimen from a plurality of incidence angles;
an X-ray optical element configured to receive radiation issuing from the specimen being imaged during operation;
an X-ray radiation detector for capturing, during operation, a plurality of variably-illuminated, low-resolution intensity X-ray images of the specimen based on X-ray radiation from the X-ray optical element; and
a processor having instructions for reconstructing a high-resolution X-ray image of the specimen by iteratively determining the high resolution X-ray image for each tile that is self-consistent with the variably-illuminated, low-resolution intensity X-ray images, wherein reconstructing the high-resolution X-ray image includes recovering phase image data.

Assignees

• California Inst Of Techn

Inventors

• Zheng Guoan
• Yang Changhuei
• Horstmeyer Roarke

Classifications

• G02B21/365

  Control or image processing arrangements for digital or video microscopes (G02B21/361, G02B21/362 take precedence) · CPC title

• G02B21/367

  providing an output produced by processing a plurality of individual source images, e.g. image tiling, montage, composite images, depth sectioning, image comparison · CPC title

• G21K7/00 Primary

  Gamma- or X-ray microscopes · CPC title

• G02B21/002

  Scanning microscopes (scanning near field optical microscopes G01Q60/18) · CPC title

• G02B27/58

  Optics for apodization or superresolution; Optical synthetic aperture systems · CPC title